Gas nitrocarburising, also known as soft nitriding, is a thermo-chemical diffusion process in which nitrogen and carbon are introduced into the surface of suitable ferrous components at relatively low temperatures. The process produces a thin, hard and wear-resistant surface layer along with improved fatigue behavior and very low distortion.
Unlike high-temperature case hardening processes, gas nitrocarburising is carried out in the ferritic range of steel, which helps maintain dimensional stability while improving surface performance. This makes it suitable for components requiring controlled surface hardening with minimal change in shape.
The process is widely used where wear resistance, scuffing resistance, seizure resistance, improved frictional behavior and some corrosion resistance are required in production components.
Gas nitrocarburising is a ferritic nitrocarburising process in which the steel is heated below the lower critical transformation range. At this temperature, nitrogen and carbon diffuse into the surface without causing bulk transformation to austenite, which is one of the main reasons for the low distortion associated with the process.
The treated layer generally consists of:
Proper process performance depends on control of:
Compared with some alternative surface hardening processes, gas nitrocarburising can provide a dense, effective surface layer with strong wear performance, low distortion and good repeatability when the cycle is properly controlled.
Goswami Heat Treatment Centre provides gas nitrocarburising services with controlled processing, practical metallurgical understanding and focus on consistent surface performance for engineering components.
Gas nitrocarburising is suitable for low carbon steels, low alloy steels and many engineering parts where a shallow, hard surface with low distortion is preferred.
Key benefits commonly associated with gas nitrocarburising include:
Gas nitriding introduces nitrogen into the surface, whereas gas nitrocarburising introduces both nitrogen and carbon. Nitrocarburising is generally used for shallower cases with strong wear performance and low distortion.
Why is gas nitrocarburising called soft nitriding?The term soft nitriding is commonly used because the process is carried out at relatively low temperature in the ferritic range and typically develops a shallow hardened layer with minimal distortion.
Does gas nitrocarburising require prehardened material?Not always. One advantage of nitrocarburising is that it can be applied to many unalloyed and low alloy steels depending on the performance requirement.
Why does this process give low distortion?Because the treatment is done below the transformation temperature of steel, there is no bulk austenitising and quench transformation as in conventional hardening.
What kind of parts are commonly treated by gas nitrocarburising?Common examples include shafts, gears, pistons, sleeves, cylinder liners, dies, screws, barrels and various automotive or industrial wear components.
Do you provide gas nitrocarburising job work for industrial components?Yes. We provide gas nitrocarburising job work for suitable engineering and tooling components subject to material, geometry and application requirements.